The JavaScript standard is ECMAScript. As of 2012, all modern browsers fully support ECMAScript 5.1. Older browsers support at least ECMAScript 3. A 6th major revision of the standard is in the works. The current progress of different new and improved features can be followed on the dedicated wiki.

This section of the site is dedicated to the JavaScript language itself, the parts that are not specific to Web pages, or other host environments. For information about APIs specific to Web pages, please see Document Object Model (DOM). Read more about how DOM and JavaScript fit together in the DOM Reference.

Other articles

Microsoft publishes documents that describe "variations, clarifications, and extensions to certain final approved web standards supported by Internet Explorer." Of these, the ones that are related to JavaScript are: